Photovoltaic power generation system, power control apparatus, and energy storage system

Abstract

A photovoltaic power generation system includes a plurality of photovoltaic batteries, a DC/DC module, a direct current bus capacitor, an energy storage component, and a power control apparatus, where an input side of the DC/DC module is coupled to the plurality of photovoltaic batteries, an output side of the DC/DC module is coupled to the direct current bus capacitor, and output electric energy provided by the photovoltaic batteries to the direct current bus capacitor; the energy storage component is coupled to the direct current bus capacitor, the power control apparatus is separately coupled to the direct current bus capacitor and the energy storage component, and is configured to: detect a first voltage of the direct current bus capacitor, and when the first voltage meets a preset compensation condition, control the energy storage component to charge the direct current bus capacitor.

1 .- 20 . (canceled) 
     
     
         21 . A photovoltaic power generation system, comprising:
 a plurality of photovoltaic batteries,   a direct current (DC)/DC module,   a direct current bus capacitor,   an energy storage; and   a power controller;   wherein:
 an input side of the DC/DC module is coupled to the plurality of photovoltaic batteries, an output side of the DC/DC module is coupled to the direct current bus capacitor, and the DC/DC module is configured to adjust an operating status of each photovoltaic battery of the plurality of photovoltaic batteries, and output electric energy provided by the plurality of photovoltaic batteries to the direct current bus capacitor; 
 the energy storage is coupled to the direct current bus capacitor, and is configured to store or provide electric energy; 
 the power controller is separately coupled to the direct current bus capacitor and the energy storage, and is configured to: detect a first voltage of the direct current bus capacitor, and when the first voltage meets a preset compensation condition, control the energy storage to charge the direct current bus capacitor; and 
 the direct current bus capacitor is configured to couple a load. 
   
     
     
         22 . The photovoltaic power generation system according to  claim 21 , wherein the power controller is configured to:
 when controlling the energy storage to charge the direct current bus capacitor, control the energy storage to provide a second voltage for the direct current bus capacitor, wherein the second voltage is determined based on the first voltage and a bus reference voltage; and   wherein the bus reference voltage is determined based on open-circuit voltages of a portion of photovoltaic batteries in the plurality of photovoltaic batteries and a peak line voltage of the load.   
     
     
         23 . The photovoltaic power generation system according to  claim 22 , wherein the power controller is further configured to:
 when the first voltage does not meet the preset compensation condition, control the energy storage to obtain first electric energy from the direct current bus capacitor and store the first electric energy, wherein the first electric energy is determined based on the first voltage and the bus reference voltage.   
     
     
         24 . The photovoltaic power generation system according to  claim 22 , wherein:
 when a maximum value in the open-circuit voltages corresponding to the portion of the photovoltaic batteries is greater than or equal to the peak line voltage of the load, the bus reference voltage is the maximum value in the open-circuit voltages corresponding to the portion of the photovoltaic batteries; or   when a maximum value in the open-circuit voltages corresponding to the portion of the photovoltaic batteries is less than the peak line voltage of the load, the bus reference voltage is the peak line voltage of the load.   
     
     
         25 . The photovoltaic power generation system according to  claim 22 , wherein the power controller is configured to control a direct current/alternating current inverter to output an alternating current of a first power for the load;
 wherein the first power is determined based on a first current and a third voltage; and   wherein the first current and the third voltage are a current and a voltage that are output by the direct current/alternating current inverter before the power controller controls the DC/DC module to perform current (I)-voltage (V) curve scanning on a portion of photovoltaic batteries in the plurality of photovoltaic batteries, or controls the DC/DC module to perform multi-peak scanning on the portion of the photovoltaic batteries.   
     
     
         26 . The photovoltaic power generation system according to  claim 22 , wherein the power controller is further coupled to the DC/DC module, and the power controller is further configured to:
 before detecting the first voltage of the direct current bus capacitor, control, in response to a first instruction, the DC/DC module to perform current (I)-voltage (V) curve scanning on a first photovoltaic battery, wherein the first photovoltaic battery is any one or more of the plurality of photovoltaic batteries; or   before detecting the first voltage of the direct current bus capacitor, control, in response to a second instruction, the DC/DC module to perform multi-peak scanning on the first photovoltaic battery.   
     
     
         27 . The photovoltaic power generation system according to  claim 21 , further comprising:
 a direct current/alternating current inverter, wherein an input side of the direct current/alternating current inverter is coupled to the direct current bus capacitor, and an output side of the direct current/alternating current inverter is configured to be coupled to the load; and   wherein the direct current/alternating current inverter is configured to convert electric energy that is output by the DC/DC module to the direct current bus capacitor into an alternating current, and provide the alternating current for the load.   
     
     
         28 . The photovoltaic power generation system according to  claim 27 , wherein the power controller is configured to control the direct current/alternating current inverter to output an alternating current of a first power for the load;
 wherein the first power is determined based on a first current and a third voltage; and   wherein the first current and the third voltage are a current and a voltage that are output by the direct current/alternating current inverter before the power controller controls the DC/DC module to perform current (I)-voltage (V) curve scanning on a portion of photovoltaic batteries in the plurality of photovoltaic batteries, or controls the DC/DC module to perform multi-peak scanning on the portion of the photovoltaic batteries.   
     
     
         29 . The photovoltaic power generation system according to  claim 28 , wherein the power controller is further coupled to the DC/DC module, and, the power controller is further configured to:
 before detecting the first voltage of the direct current bus capacitor, control, in response to a first instruction, the DC/DC module to perform IV curve scanning on a first photovoltaic battery, wherein the first photovoltaic battery is any one or more of the plurality of photovoltaic batteries; or   before detecting the first voltage of the direct current bus capacitor, control, in response to a second instruction, the DC/DC module to perform multi-peak scanning on the first photovoltaic battery.   
     
     
         30 . The photovoltaic power generation system according to  claim 21 , wherein the power controller is further coupled to the DC/DC module, and the power controller is further configured to:
 control, in response to a first instruction, the DC/DC module to perform current (I)-voltage (V) curve scanning on a first photovoltaic battery, wherein the first photovoltaic battery is any one or more of the plurality of photovoltaic batteries; or   before detecting the first voltage of the direct current bus capacitor, control, in response to a second instruction, the DC/DC module to perform multi-peak scanning on the first photovoltaic battery.   
     
     
         31 . A photovoltaic power generation system, comprising a plurality of photovoltaic batteries;
 a plurality of direct current/direct current conversion circuits;   a direct current bus capacitor;   an energy storage;   a direct current/alternating current inverter; and   a power controller; and   wherein:
 an input side of each of the direct current/direct current conversion circuits is coupled to one photovoltaic battery of the plurality of photovoltaic batteries, an output side of each of the direct current/direct current conversion circuits is coupled to the direct current bus capacitor, and each of the direct current/direct current conversion circuits is configured to:
 adjust an operating status of the one coupled photovoltaic battery, and output electric energy provided by the one coupled photovoltaic battery to the direct current bus capacitor; 
 
 the energy storage is coupled to the direct current bus capacitor, and is configured to store or provide electric energy; 
 an input side of the direct current/alternating current inverter is coupled to the direct current bus capacitor, and an output side of the direct current/alternating current inverter is coupled to a load, and is configured to convert electric energy on the direct current bus capacitor into an alternating current, and provide the alternating current for the load; and 
 the power controller is separately coupled to the plurality of direct current/direct current conversion circuits, the direct current bus capacitor, the energy storage, and the direct current/alternating current inverter, and the power controller is configured to: 
 after receiving a current (I)-voltage (V) curve scanning instruction, determine a first power provided by the direct current/alternating current inverter to the load, the instruction is used to indicate performing IV curve scanning on a first photovoltaic battery, wherein the first photovoltaic battery is at least one photovoltaic battery in the plurality of photovoltaic batteries; 
 control a first direct current/direct current conversion circuit connected to each photovoltaic battery in the first photovoltaic battery to adjust each photovoltaic battery to operate in an open-circuit state, and determine an open-circuit voltage of each photovoltaic battery; and 
 determine a bus reference voltage based on the open-circuit voltage of each photovoltaic battery in the first photovoltaic battery and a peak line voltage of the load, wherein the bus reference voltage is a voltage threshold configured for determining whether the energy storage charges the direct current bus capacitor or obtains electric energy from the direct current bus capacitor. 
   
     
     
         32 . The photovoltaic power generation system according to  claim 31 , wherein the power controller is further configured to:
 control, in response to receiving the IV curve scanning instruction, the first direct current/direct current conversion circuit to perform IV curve scanning on the first photovoltaic battery;   detect a first voltage of the direct current bus capacitor in a process in which the first direct current/direct current conversion circuit performs IV curve scanning on the first photovoltaic battery;   when the first voltage is detected to be less than the bus reference voltage, control the energy storage to charge the direct current bus capacitor, or when the first voltage is detected to be greater than the bus reference voltage, control the energy storage to obtain first electric energy from the direct current bus capacitor and store the first electric energy, wherein the first electric energy is determined based on the first voltage and the bus reference voltage; and   in the process in which the first direct current/direct current conversion circuit performs IV curve scanning on the first photovoltaic battery, control the direct current/alternating current inverter to work in a constant power output state, wherein the constant power output state comprises a state of converting a direct current on the direct current bus capacitor into an alternating current of a second power and providing the alternating current to the load, and a difference between the second power and a first power is less than a preset power threshold.   
     
     
         33 . The photovoltaic power generation system according to  claim 32 , wherein the power controller is configured to:
 when controlling the energy storage to charge the direct current bus capacitor, control the energy storage to provide a second voltage for the direct current bus capacitor, wherein the second voltage is determined based on the first voltage and the bus reference voltage.   
     
     
         34 . The photovoltaic power generation system according to  claim 31 , wherein the power controller is further configured to:
 control a direct current/direct current conversion circuit other than the first direct current/direct current conversion circuit in the plurality of direct current/direct current conversion circuits to work in a maximum power point tracking (MPPT) state.   
     
     
         35 . The photovoltaic power generation system according to  claim 31 , wherein the bus reference voltage is a maximum value of the open-circuit voltage of each photovoltaic battery in the first photovoltaic battery and the peak line voltage of the load. 
     
     
         36 . The photovoltaic power generation system according to  claim 32 , wherein the first direct current/direct current conversion circuit is configured to:
 when performing IV curve scanning on the first photovoltaic battery, adjust an output voltage of each photovoltaic battery in the first photovoltaic battery, and record output currents of each photovoltaic battery at different output voltages; and   send the recorded output currents of each photovoltaic battery in the first photovoltaic battery at the different output voltages to a first device, wherein the first device is a device that sends the IV curve scanning instruction.   
     
     
         37 . A power control apparatus, comprising:
 a plurality of photovoltaic batteries;   a DC/DC module;   a direct current bus capacitor; and   an energy storage;   a power control circuit; and   wherein:
 an input side of the DC/DC module is coupled to the plurality of photovoltaic batteries, an output side of the DC/DC module is coupled to the direct current bus capacitor, the energy storage is coupled to the direct current bus capacitor, and the direct current bus capacitor is configured to couple a load; 
 the power control circuit comprises a detection circuit and a control circuit; 
 the detection circuit is configured to detect a first voltage of the direct current bus capacitor; and 
 the control circuit is coupled to the detection circuit, and is configured to: when it is determined that the first voltage meets a preset compensation condition, control the energy storage to charge the direct current bus capacitor. 
   
     
     
         38 . The apparatus according to  claim 37 , wherein the control circuit is configured to:
 when controlling the energy storage to charge the direct current bus capacitor, control the energy storage to provide a second voltage for the direct current bus capacitor, wherein the second voltage is determined based on the first voltage and a bus reference voltage; and   wherein the bus reference voltage is determined based on open-circuit voltages of a portion of photovoltaic batteries in the plurality of photovoltaic batteries and a peak line voltage of the load.   
     
     
         39 . The apparatus according to  claim 38 , wherein the control circuit is further configured to:
 when it is determined that the first voltage does not meet the preset compensation condition, control the energy storage to obtain first electric energy from the direct current bus capacitor and store the first electric energy, wherein the first electric energy is determined based on the first voltage and the bus reference voltage.   
     
     
         40 . The apparatus according to  claim 38 , wherein:
 when a maximum value in the open-circuit voltages corresponding to the portion of the photovoltaic batteries is greater than or equal to the peak line voltage of the load, the bus reference voltage is determined as the maximum value in the open-circuit voltages corresponding to the portion of the photovoltaic batteries; or   when a maximum value in the open-circuit voltages corresponding to the portion of the photovoltaic batteries is less than the peak line voltage of the load, the bus reference voltage is determined as the peak line voltage of the load.